Thin Films of a Tetracationic Porphyrin

Langmuir–Blodgett films of the tetracationic porphyrin tetrakis(octadecyl-4-pyridinium)porphinatozinc(II) bromide transferred from subphases containing different salts were studied using X-ray photoelectron spectroscopy (XPS) and X-ray reflectometry. In contrast to previous results at the air/water interface, we found that the porphyrin adopted a fixed conformation at the air/solid interface regardless of composition of the subphase or whether the films were transferred above or below the primary phase transition. This conformation was assigned to the formation of an interdigitated bilayer structure.

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SPECTROSCOPIC CHARACTERIZATIONS OF NONAMPHIPHILIC 2,5-BIS (5-TERT-BUTYL-BENZOXAZOLYL)-THIOPHENE MOLECULES AT THE AIR–WATER INTERFACE AND IN LANGMUIR–BLODGETT FILMS

Surface Review and Letters ◽

10.1142/s0218625x08012086 ◽

2008 ◽

Vol 15 (06) ◽

pp. 889-896 ◽

Cited By ~ 3

Author(s):

S. BISWAS ◽

SYED ARSHAD HUSSAIN ◽

D. BHATTACHARJEE

Keyword(s):

Phase Transition ◽

Surface Pressure ◽

Spectroscopic Studies ◽

Repulsive Interaction ◽

Water Interface ◽

Thiophene Derivative ◽

Langmuir Blodgett ◽

Tert Butyl ◽

Air Water Interface ◽

Langmuir Blodgett Films

This paper reports the π–A isotherm and spectroscopic characterizations of mixed Langmuir and Langmuir–Blodgett films of a nonamphiphilic thiophene derivative, namely, 2,5-Bis (5-tert-butyl-benzoxazolyl)-thiophene (BBOT) molecules, mixed with polymethyl methacrylate (PMMA) and stearic acid (SA). The π–A isotherms and molefraction vs. area per molecule studies indicate some repulsive interaction between sample (BBOT) and matrix (PMMA or SA) molecules. At higher surface pressure in the SA mixed BBOT Langmuir monolayer, a phase transition occurs, which has been revealed by π–A isotherm studies. UV-vis absorption and fluorescence spectroscopic studies confirm this phase transition and closer association of BBOT molecules. Spectroscopic studies of LB films lifted at higher surface pressure clearly confirm the presence of dimmers and higher-order n-meric sites.

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Metal Cyanide Networks Formed at an Air-Water Interface: Structure and Magnetic Properties

MRS Proceedings ◽

10.1557/proc-658-gg5.2 ◽

2000 ◽

Vol 658 ◽

Author(s):

Jeffrey T. Culp ◽

A. Nicole Morgan ◽

Mark W. Meisel ◽

Daniel R. Talham

Keyword(s):

Thin Films ◽

Photoelectron Spectroscopy ◽

Magnetic Measurements ◽

Exchange Interactions ◽

Water Interface ◽

X Ray Diffraction ◽

X Ray ◽

Metal Cyanide ◽

Air Water Interface ◽

Show Evidence

ABSTRACTExtended two-dimensional coordinate covalent networks have been formed at an air-water interface by condensing a Langmuir monolayer of an amphiphillic pentacyanoferrate(III) complex and aqueous nickel(II) ions. The cyanide-bridged arrays were transferred to solid supports by the Langmuir-Blodgett (LB) technique. The resulting thin films were structurally characterized by UV-Vis and FT-IR spectroscopies, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), and SQUID magnetometry. Magnetic measurements on the thin films transferred to Mylar show evidence for ferromagnetic exchange interactions between the S = 1/2 Fe(III) and S = 1 Ni(II) centers.

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Chlorophyll a–violaxanthin interactions in monolayers at air–water interface and in Langmuir–Blodgett films

Colloids and Surfaces B Biointerfaces ◽

10.1016/s0927-7765(00)00132-6 ◽

2000 ◽

Vol 19 (2) ◽

pp. 117-125 ◽

Cited By ~ 4

Author(s):

Wieslaw I Gruszecki ◽

Bogumil Zelent ◽

Heidar-Ali Tajmir-Riahi ◽

Gongming Wang ◽

Toufik Taleb ◽

...

Keyword(s):

Chlorophyll A ◽

Water Interface ◽

Langmuir Blodgett ◽

Air Water Interface ◽

Langmuir Blodgett Films

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Effects of a central metal on the organization of 5,10,15,20-tetra-(p-chlorophenyl)–rare earth porphyrin hydroxyl compound at the air/water interface and in Langmuir–Blodgett films

Journal of Colloid and Interface Science ◽

10.1016/j.jcis.2004.10.053 ◽

2005 ◽

Vol 284 (2) ◽

pp. 582-592 ◽

Cited By ~ 7

Author(s):

Xiaoling Li ◽

Weiqing Xu ◽

Tamitake Itoh ◽

Akifumi Ikehata ◽

Bing Zhao ◽

...

Keyword(s):

Rare Earth ◽

Central Metal ◽

Water Interface ◽

Langmuir Blodgett ◽

Air Water Interface ◽

Langmuir Blodgett Films

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Thermochromic VO2 Thin Film Prepared by Post Annealing Treatment of V2O5 Thin Film

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.747 ◽

2009 ◽

Vol 79-82 ◽

pp. 747-750 ◽

Cited By ~ 12

Author(s):

Dong Qing Liu ◽

Wen Wei Zheng ◽

Hai Feng Cheng ◽

Hai Tao Liu

Keyword(s):

Thin Film ◽

Thin Films ◽

Phase Transition ◽

Photoelectron Spectroscopy ◽

Sol Gel ◽

Annealing Treatment ◽

Simple Method ◽

X Ray ◽

Post Annealing ◽

Vo2 Thin Films

Thermochromic vanadium dioxide (VO2) exhibits a semi-conducting to metallic phase transition at about 68°C, involving strong variations in electrical and optical properties. A simple method was proposed to prepare VO2 thin films from easily gained V2O5 thin films. The detailed thermodynamic calculation was done and the results show that V2O5 will decompose to VO2 when the post annealing temperature reaches 550°C at the atmospheric pressure of less than 0.06Pa. The initial V2O5 films were prepared by sol-gel method on fused-quartz substrates. Different post annealing conditions were studied. The derived VO2 thin film samples were characterized using X-ray diffraction and X-ray photoelectron spectroscopy. The electrical resistance and infrared emissivity of VO2 thin films under different temperatures were measured. The results show that the VO2 thin film derived from the V2O5 thin film annealed at 550°C for 10 hours is pure dioxide of vanadium without other valences. It was observed that the resistance of VO2 thin film with thickness about 600nm can change by 4 orders of magnitude and the 7.5-14μm emissivity can change by 0.6 during the phase transition.

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